Internal-combustion engine ventilating system



Dec, 1, 1953 R. T. DOUGHTY INTERNAL-COMBUSTION ENGINE VENTILATING SYSTEM Filed Jan. 24, 1951 2 Sheets-Sheet l ISnventor s, .W (w I dun W I'll III! I 1 T T FA... Q

(Ittorneg Dec. 1, 1953 R. T. DOUGHTY INTERNAL-COMBUSTION ENGINE VENTILATING SYSTEM Filed Jan. 24, 1951 Z'Sheets-Sheet 2 a g g u y Gttomega Patented Dec. 1, 1953 UNETED STATES INTERNAL-COMBUSTION ENGINE VENTILATING SYSTEM Robert T. Doughty, Detroit, Mich assignor to General Motors Corporation, Detroit, Mich., a

corporation of Delaware Application January 24, 1951, Serial No. 207,601

9 Claims.

This invention relates to ventilation of internal combustion engines and the like and particularly to means for mounting and driving a ventilating fan therein.

It is conventional practice to provide for ventilating internal combustion engines by arranging inlet and outlet openings to the crankcase and other internal compartments at points which will enable the natural drafts obtained in operation to expel unwanted accumulated. gases. Where the engine is used to drive a vehicle additional draft for ventilation purposes is obtained by ar ranging the ventilating outlet in the slip stream of the vehicle whereby a certain amount of suction is obtained to increase the rate of air circulation through the engine. In modern day en gines however where it is desired to have a rather tortuous ventilating circuit which will insure adequate ventilation of other compartments in adtherefore to provide an improved mounting and driving means for a ventilating fan for use in internal combustion engines and the like.

It is a further object of my invention to provide an improved ventilating system for internal combustion engines including a positive axial flow fan mounted on a camshaft driven auxiliary drive and eiiective to transfer ventilating gases from the crankcase to the valve compartment.

Reference is now made to the drawings showing a preferred embodiment of the invention as applied to the ventilating system of an automotive vehicleinternal combustion engine having an ignition distributor and oil pump drive geared inline with each other to the engine camshaft, my ventilating fan being mounted coaxial with this drive and keyed for rotation therewith by means of tab-like lugs interfitting between the tongued and grooved ends of the distributor drive coupling. It will be understood, of course, that my invention in its broader aspects will have application to other types of engines and that my fan mounting and driving arrangement may be applied in similar manner to tongued and grooved shaft couplings generally.

Figure 1 is a longitudinal elevational view of (Cl. 123-4L86) an internal combustion engine incorporating my invention, with parts broken away and in section.

Figure 2 is an enlarged sectional view substantially on line 22 of Figure 1.

Figure 3 is a detail sectional view substantially on line 3--3 of Figure 2.

Figure l is an exploded View in perspective of my fan and the tongued and grooved ends of the distributor drive shafts between which the fan is mounted in the engine.

Referring now to the drawings in detail, Figure 1 shows a multi-cylinder internal combustion engine of the in-line type having a casing or cylinder block 2 extending longitudinally of the engine and journaling the crankshaft ii to which is coupled the usual external engine cooling fan 6 at the front end of the engine by a fan belt 8. The cylinder block 2 forms a crankcase It in which is provided bearings l2 for the crankshaft 4 and bearings 14 for the usual camshaft It also extending longitudinally of the engine. Suppor ing the front and rear crankshaft and camshaft bearings l2 and M are the front and rear walls It and 29 respectively of the crankcase and these walls It and 25 join at each side of the engine with the side walls (not shown) of the crankcase. Forming the top wall of the crankcase is a wall 22 and extending above this wall 22 is an extension 2d of the crankcase front wall It and an extension 26 of the crankcase rear wall 2%. The side walls of the crankcase similarly extend above the wall 22 and form a valve compartment 28 directly above the crankcase. Reinforcing the cylinder block and supporting the intermediate bearings for the crankshaft and camshaft are walls 30 which depend from the wall 22. The rear wall 20 and its extension 25 serve to close the rear end of both the crankcase and the valve compartment and, whereas the front wall extension 24 similarly closes the front end of the valve compartment 23, the front end of the crankcase is open below the wall is to the timing gear compartment 32 formed between the walls I8 and 2d and usual cover 32 enclosing the timing gears (not shown) interconnecting the crankshaft and camshaft. The bottom of the crankcase is closed by the usual oil pan 35, and the top of the valve compartment 28 is closed by a cover designated generally at 38 having spaced apart inner and outer walls it and i2 respectively, forming between them a ventilating air jacket or passage it. Bolts t6 are shown passing through aligned openings in the jacket walls ill and is for anchoring the valve compartment cover in place on the cylinder block.

In accordance with conventional practice the engine ignition distibutor 48 and the engine oil pump (not shown), which is located in the sump Eli of the oil pan have a common drive means geared tathe camshaft it. Preferably this drive means is located adjacent one extreme end. of the engine for r asons which will be hereinafter apparent extends through an opening '52 provided in the common wall 222 between the crankcase i i and the valve compartment 28'. distributor drive gear on the camshaft i-t meshes with a is rotatably supported on; the. oil' pump drive shaft journaled in upper and lower brackets 59 and 52 anchored to the cylinder block 2. The

distributor driven gear :58 rotatablybears on--th'eupper face of the upper bracket Eli. and maytending hollow hub or shaft portion 68 which. terminates in an end face having a transverse groove or slot i2. Extending into the upper end of. the hollow portion i the lower end' of the distributor shaft The shaft it is journaled inthe stationary distributor shaft housing it which extends through the cylinder block and clamped in place thereon by" a suitable crab 18; The lower end of the distributor shaft M has an integrally associated spline or tongue portion 3. 3 which is received in and is interengaged by the groove on the distributor driven shaft E3; The opening 52 is substantially larger than the periphery of the shaft 53 and the clearance therebetween provides communication between the crankcase H3 and the valve. compartment 28.

Secured to the cylinder block 2 opposite an opening, therein at the top of the timing gear compartment is an engine oil filler pipe 85' whichalso serves as aventilating inlet'du'ct. The upper end of this pipe 8 may be provided with the. usual cap which. has a depending skirt.

portion 35 fitting loosely about the pipe andapertured at 9% to permit air. being drawn into the upper end of the pipe. A ventilating outlet duct or pipe 92 is connected to. an opening through the upper wall oi the valve gear compartment;

cover. adjacent the rear end of the engine, and

this pipe leads downwardly to a point adjacent wardly through the crankcase to the rear end of the engine, thence upwardly through the-opening 52' in the wall thence forwardly of the engine through the valve gear compartment 28' to the opening "53, and then rearwardly again through the jacket ii and out through the pipe,

In. order that the. circulation. of air: through the engine may.- be made positive atiallengine speeds I provide aian which is supported by and rotates with the distributor driving means in the opening As best shown in Figures 2 .2,

this fan may be cheaply and simply formed from sheetrnetal to provide a cylindrical core. 96 open atboth ends and of a diameter which will have. a slidablefit about-the hub 53 of the distributor ributor drivengear 52-. which.

a ventilating circuit driven gear. Secured as by welding or any suitable means on the outer periphery of the core 93 are a plurality of helical blades 98 which project radially outward toward the walls of the opening 52. As means to insure rotation of the fan during engine operation the upper end of the core 93 is provided with radially inwardly extending tab-like lugs !8fl,.lanced out of. the sheet metal core, and disposed in the opposite ends of the transverse groove l2. As shown in Figure 2, these lugs Hit rest on the bottom of the groove 72 and are retained in place therein by the lower end faces lfii of the tongue portion it on the end of. the; dis ributor: shaft '54. Thus the fan is made to-rotate-with the distributor driven gear shaft. 62- anddistributor shaft 54 and is also suitably locatedaxially of the opening To increase the fan efficiency I also provide a sheet metal shroud 102 made of sheet metal which is press fitted or otherwise suitably secured in the opening 52. During engine operation a. positive flow of air from the crankcaseto the valve gear compartment is. thus induced.

While I have illustrated my fan as mounted on the. distributor drive shaft. of an internal combustion engine, it will be obvious to those skilled inthe artthat the same may be applied to other shafts having a tongue and groove driving connection. between them and where it is desired to effect an axial fiow of air therealong. Further, while I have described my invention in detail in. its present preferred embodiment, various changes and modifications may, of course, be made therein without departing from the spirit and scope of the appended claims.

I claim:

1. In a ventilation system for an internal coinbustionengine, a cylinder blocl; having a crankcase and a valve compartment separated by a common. wall, said wall having an. opening proa engaging tongue and slot portions rotatably keyed. to i said. members: between said tongue and slot portions.

2. In a ventilating system for. an'engine, an enginecasinghaving a wall provided with opening,, a rotatively driven firstmember extending through-.saidopening, asecond member. longitudinally adjacent said first memberand rotatable therewith, positively interengaged: rotary driving faces on the adjacent endsof said members, and aniinpeller coaxially rotatable'with one of said members and having a driving lug' disposed between said interengaged faces.

3. In an. internal combustion engine, a cylinder. bloeleiorming a crankcaseanda valve cornpartment. interconnected. by. an opening. said crankcase] having a. ventilating. inlet. and said valve. compartment having a ventilating outlet, an engine ignition distributor having. a rotary driving, means extending through said opening, and a ventilating fan rotatable in said opening with said drivingmeans.

hIn an. internal.combustionengine having a cylinder. block forming acranlzcase anda valve compartment. with a. separating wall therebetween having an opening through which gas may flow between the crankcase and the valve compartment, a oamshaftjournaled in the block on the crankcase-side of said wall, a distributor drive shaft geared to the camshaft:andzextending coaxiallyinto i said opening; a; transversely extending groove in the extended end of said drive shaft, an axial flow ventilating fan rotatable in said opening with said drive shaft, said fan having a cylindrical sheet metal core supporting a series of outwardly radiating helical blades, one end of said core having a lanced-out radially inward extending lug seated in said groove, a distributor shaft extending into the valve compartment and having a driving tongue on its inner end received in said groove, and a cylindrical sheet metal shroud circumferentially enclosing said blades and secured to the casing within said opening.

5. In an internal combustion engine having a crankcase and a valve compartment separated by a common wall extending longitudinally of the engine, a camshaft supported in opposite ends of the crankcase, a camshaft driving gear compartment at one end of the engine, an imperforate wall at said one end of the engine between the valve and gear compartments and extending into the crankcase, said gear compartment and crankcase being in communication opposite the extended end of said imperforate wall, a ventilating inlet duct connected to the gear compartment opposite the valve compartment, said common wall having an opening adjacent the other end of the engine providing communication between the crankcase and valve compartment, camshaft driven means rotated about an axis extending through said opening, said driven means including axially adjacent shaft members having a tongue and groove on their adjacent ends forming a rotary driving connection therebetween, an axial flow fan in said opening rotatable on said axis, said fan having integrally associated radially extending lugs engaged in said groove and securing said fan for rotation with said shaft members, a cover for the valve compartment having spaced apart irmer and outer walls forming a jacket extending longitudinally of the engine with an opening to the valve compartment at said one end of the engine, and a ventilating outlet duct connected to said jacket at said other end of the engine.

6. The combination with a rotatively driven shaft and a. generally coaxial and longitudinally of which shafts have a spline and a spline receiving groove respectively for effecting a rotary driving connection therebetween, of an impeller rotatable with said shafts having a generally radially projecting lug disposed inwardly of said spline within said groove.

7. In combination, axially adjacent aligned driving and driven shafts provided on their adjacent ends with a tongue and a tongue receiving groove in rotatively interlocked relation, and a rotary impeller having a core embracing one of said shafts with an inwardly projecting lug disposed between said shafts and retained in said groove by said tongue.

8. In a ventilation system for an engine or the like having crankcase and valve compartments with a partition therebetween, said partition having an opening, an engine driven shaft of smaller cross section than said opening and extending therethrough, and an axial flow fan secured to said shaft within opening for delivering air from one compartment to the other.

9. In a ventilating system for an engine or the like having two enclosed compartments separated by a partition, engine driven means extending through said partition, said partition having an opening surrounding said means accommodating passage of air from one compartment to the other, and an axial flow fan carried by said means within said opening.

ROBERT T. DOUGHTY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,329,587 Dunham Feb. 3, 1920 1,345,048 Weidely June 29, 1920 1,872,609 Schittke Aug. 16, 1932 2,029,216 Barker Jan. 28, 1936 2,252,974 Lowther Aug. 19, 1941 2,389,140 Enblom Nov. 20, 1945 FOREIGN PATENTS Number Country Date 2 318,682 Germany Feb. 5, 1920 

